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A First-in-Human Safety and Efficacy Study of ALN-CFB, a Small Interfering RNA (siRNA) Targeting Complement Factor B, in Adult Participants With Paroxysmal Nocturnal Hemoglobinuria With Persistent Anemia on a C5 Inhibitor

A Randomized, Double-Blind, Placebo-Controlled, First-In-Human Study of the Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of ALN-CFB, an Investigational siRNA Therapeutic Against Complement Factor B, in Participants With Paroxysmal Nocturnal Hemoglobinuria and Persistent Anemia on Approved C5-Inhibitor Therapy

Status
Recruiting
Phases
Phase 1Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07187401
Enrollment
24
Registered
2025-09-23
Start date
2026-02-11
Completion date
2031-07-15
Last updated
2026-07-09

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Paroxysmal Nocturnal Hemoglobinuria (PNH), Persistent Anemia

Keywords

C5 inhibitor, Complement Factor B (CFB) protein, Red Blood Cells

Brief summary

This study is researching an experimental drug called ALN-CFB. The study is focused on people with Paroxysmal Nocturnal Hemoglobinuria (PNH) who are currently taking a complement component C5 inhibitor ("C5-inhibitor") and continue to have anemia (low red blood cell count). The aim of the study is to see how tolerable ALN-CFB is compared to placebo. A placebo looks like the study drug but does not contain any drug. The study is looking at several other research questions, including: * What side effects may happen from taking ALN-CFB * How much ALN-CFB is in the blood at different times * How much Complement Factor B (CFB) protein levels in the blood are affected by ALN-CFB

Detailed description

The protocol will be amended to describe Part B of the study after Part A data have been analyzed.

Interventions

DRUGALN-CFB

Administered as defined in the protocol

DRUGPlacebo

Administered as defined in the protocol

Sponsors

Regeneron Pharmaceuticals
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

Key Inclusion Criteria: 1. Has been diagnosed with PNH confirmed by a history of high flow cytometry from prior testing 2. Treated with a stable dose of C5 inhibitor (eculizumab or approved eculizumab biosimilar, ravulizumab, or crovalimab) for at least 24 weeks prior to screening visit, as described in the protocol 3. Has hemoglobin ≤10.5 g/dL at screening visit 1, with evidence of anemia prior to this visit, as described in the protocol 4. Has peripheral blood reticulocyte count of ≥100 x 10\^9/L at screening visit 1 Key

Exclusion criteria

1. Has history of bone marrow transplantation or receipt of an organ transplant 2. Has history of meningococcal infection or similar recurrent infections by other encapsulated bacterial organisms 3. Has any active, ongoing infection or a recent infection requiring ongoing systemic treatment with antibiotics, antivirals, or antifungals within 2 weeks of screening or during the screening period 4. Has laboratory evidence of bone marrow failure, as described in the protocol 5. Have recent, unstable medical conditions, not related to PNH or PNH-related complications, as described in the protocol NOTE: Other Protocol Defined Inclusion /

Design outcomes

Primary

MeasureTime frame
Occurrence of Treatment-Emergent Adverse Events (TEAEs)Through 365 Days
Severity of TEAEsThrough 365 Days

Secondary

MeasureTime frame
Concentrations of combined ALN-CFB and major metabolites in plasmaThrough 365 Days
Concentrations of combined ALN-CFB and major metabolites in urineThrough 24 Hours following ALN-CFB administration
Absolute change from baseline in CFB concentrationBaseline, Through 365 Days
Percentage change from baseline in CFB concentrationBaseline, Through 365 Days

Countries

Canada, South Korea, United Kingdom

Contacts

CONTACTClinical Trials Administrator
clinicaltrials@regeneron.com844-734-6643
STUDY_DIRECTORClinical Trial Management

Regeneron Pharmaceuticals

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jul 10, 2026